From the Guidelines
Fish oil supplements may increase the risk of atrial fibrillation (AFib), particularly at higher doses, as suggested by a recent study published in 2021 1. The study found that patients taking EPA and DHA supplements had a higher incidence of AFib (7.2%) compared to those taking a placebo (4.0%), although the difference was not statistically significant (P=0.06) 1. Key points to consider include:
- The study involved 1027 patients with a mean age of 75 years, who were followed up for 2 years 1.
- The dosage of EPA and DHA used in the study was 930 mg and 660 mg, respectively, which is a relatively high dose 1.
- Another study published in 2020 found no significant association between omega-3 carboxylic acid supplementation and the risk of cardiovascular events, including AFib 1. However, it is essential to weigh the potential benefits of fish oil supplements against the risks, particularly for individuals with existing heart rhythm issues or AFib risk factors. If you are considering taking fish oil supplements, it is advisable to discuss the potential benefits and risks with your healthcare provider, especially if you are taking high doses or have underlying health conditions. Overall, while the evidence is not conclusive, it suggests that high doses of fish oil supplements may increase the risk of AFib, and moderate doses (around 1 gram daily or less) may be safer for most people 1.
From the Research
Fish Oil and Atrial Fibrillation
- The relationship between fish oil supplementation and atrial fibrillation (AF) is complex, with some studies suggesting a potential benefit in reducing the risk of AF recurrence 2, while others indicate a possible increased risk of incident AF 3.
- A 2022 study found that habitual fish oil supplementation was associated with a higher rate of incident AF, particularly in individuals without cardiovascular disease at baseline 3.
- In contrast, a 2012 study demonstrated that long-term omega-3 polyunsaturated fatty acid supplementation reduced the recurrence of persistent AF after electrical cardioversion 2.
- Another study from 2012 discussed the potential anti-arrhythmic and pro-arrhythmic effects of omega-3 fatty acids, highlighting the need for further research to fully understand their impact on AF 4.
Mechanisms and Potential Benefits
- Fish oil is rich in unsaturated fatty acids, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which may have anti-inflammatory, anti-oxidative, and cardiovascular protective effects 5.
- The omega-3 index, which measures EPA and DHA levels in red blood cells, may be a useful tool in assessing an individual's risk of sudden cardiac death and potentially guiding fish oil supplementation 4.
Risks and Considerations
- While fish oil supplementation may have potential benefits, it is essential to consider the risks of ingesting pollutants, such as mercury, and to follow proper dosages and guidelines 6.
- The association between fish oil supplementation and AF risk may be modified by genetic AF predisposition, baseline cardiovascular disease status, and background oily fish consumption 3.